Typically, lighted signs such as are utilized for indicating an "exit", or "fire escape" and the like, generally include a transparent or translucent colored lens or cover screen interposed in front of at least one florescent or incandescent bulb. Such devices, however, require relatively expensive and frequent maintenance, i.e., bulb replacement, provide noticeably pinpoint light source and high operation cost.
Some conventionally lighted signs use bulbs to either form the word(s) or are arranged contiguously in alignment with the transparent word portions of the sign. Obviously, the letters of the sign in front of the bulbs appear much brighter than those portions spaced further from the bulb, the result being an inefficient, relatively expensive and esthetically unpleasant illuminated sign. In addition, the burnout of one or more such bulbs is typically noticeable by observers and information distortion may result.
These devices have numerous deficiencies such as being sumptuous in component parts, being cumbersome in design, requiring considerable maintenance, and subject to failure, and are relatively expensive and complex to manufacture.